Papers by Keyword: Linear Motion

Abstract: This paper presents the works carried out by the authors in the field of structural and functional optimization of industrial robot's numerically controlled (NC) axes. The study includes the results obtained in the research stage of the experimental measurements performed to evaluate the electrical servomotor's thermal behavior using a thermal (infrared) imaging camera. The analyzed servomotor is a brushless servomotor integrated in an experimental stand for linear motion NC axis experimental research, existing in the MMS department from EMTS faculty. Supplementary to the driving servomotor, the experimental stand includes a belt drive transmission, a ball screw - bearings assembly and a driven element guided by ball rail system. This experimental research phase is part of the doctoral thesis of first author and was conducted in order to validate the mathematical models developed in the PhD thesis. Thus, experimental results presented in the paper have been used to validate first mathematical models for electric motor's preliminary selection and checking, (performed by determining the total reflected inertia of the mechanical system on motor shaft level) as well as the mathematical models for final selection and checking (by evaluating the servomotor's thermal energy dissipation, and servomotor's internal and external maximum operating temperature). Second, the experimental results have been used to validate the assisted simulation for structural and functional optimization of industrial robot's NC axes based on both servomotor and drive's thermal behavior analysis, performed in the thesis by means of a dedicated commercial software package.

Abstract: Precision motion system is driven directly by high frequency linear motion platform, eliminating the adverse effects brought by mechanical transmission, and greatly improving the rapid reaction capability and the control accuracy of feedback system. The linear motion platform is widely used in various types of high-speed, precision machining equipment. In the paper, the one-dimensional linear motion platform is described, and design solution of mechanical part and control system is also introduced, including working principle and structure of voice coil motor, control methods of grating sensors, circuit of grating sensor, drive and control circuit. Displacement control, speed control and output force control of the one-dimensional linear motion control platform can be achieved. So the one-dimensional linear motion platform can be applied in the movement device in high-precision and high-speed.

Abstract: In order to adapt to the needs of internal combustion engine speed variation of the turbocharger. Using waste gas regulator control exhaust gas inlet device. The effect of exhaust gas regulator is for adjusting the gas flow velocity and direction. When the internal combustion engine running at low speed raising the impeller speed. Exhaust gas regulator and axial moving blades rotating blades of two kinds of structure. The axial moving blade structure is changing the way nozzle ring opening work. Rotating blade structure is working on changing the way of blade Angle. Exhaust gas to adjust the turbocharger is a control of internal combustion engine air pressurization value of the speed changes.

Abstract: A two-degrees-of-freedom voice coil motor and its control system are proposed for linear and rotary motions with high speed. This VCM consists of two individual motion parts driven by two separated DSP embedded controllers. For servo control of the VCM, an improved PID control algorithm is adopted. The performance of the control algorithm is evaluated under actual environment. When the targets of position and angle are set at 5mm and 15°, the time response shows 48ms and 70.4ms settling time with 5μm and 3’ steady state error without overshoot. Settling time is reduced to 36% as compared to that of original PID controller.

Abstract: In the present work, investigations by high frequency resonance technique for diagnosis of defect frequencies of linear motion unit are reported. Raw vibration signature of the moving parts at different speeds of operation has been demodulated. Envelope detected spectrum is analyzed to evaluate various defect frequencies and their energy levels. Experimentally evaluated frequencies are compared with theoretically determined defect frequencies. These frequency values and their energy levels are used to monitor intrinsic condition of linear motion unit as well as to establish severity of existing/developed defects on the LM guide and inside the LM block. Relative comparisons of linear motion units of the same type are made at various operating speeds under identical conditions of operation on the basis of identified defect frequencies and severity of defects.

Abstract: The article presents the structural and geometric synthesis and mechanical parameter choice for a manipulation mechanism for measurement microphone positioning during acoustical tests in anechoic chamber. Usually the aims of acoustical measurements in anechoic chamber are: noise source Sound Power Level estimation, electroacoustical transducer directional characteristics measurement, sound diffusing characteristic of a structure measurement, measurement of Sound Pressure Level on a given measurement grid The specific of that kind of measurements brings up the need of measurement microphone positioning in many points of the measurement space accordingly to relevant standards. In most cases during the tests it is necessary to position the microphone in certain points on the hemisphere. In such cases utilizing of typical microphone stands impedes the measurement and extends the time needed for the tests. Those circumstances led to idea of measurement manipulator construction that would allow changing the microphone position during the measurement accordingly to a specified algorithm. The following assumptions for construction were taken: measurement microphone moves on the hemisphere with a maximal radius of 2 m, the weight of transported object (microphone or other) does not exceed 1 kg, positioning accuracy is 1 mm. Structural and geometric synthesis was made taking into account mounting conditions in anechoic chamber in Department of Mechanics and Vibroacoustics AGH-UST. There were several variants labored that fulfilled the assumptions. The choice of particular solution was made based on: • manipulator drives possible installation analysis with regard to their acoustical noise emission • structure stiffness analysis with regard to assumed positioning accuracy of the microphone Finally a modular construction of manipulator was chosen, which is composed of industrial turntable (built in the level of the wire netting) and two linear motion modules (long axis, short axis). That solution means that the device under test fixed on the turntable rotates in the range of 2π, and the measurement microphone moves on the track of one quarter of a circle. Specific angular position of the linear modules was chosen which allows minimal dimensions of linear modules. Simultaneously the control structure and the software part are developed. The usefulness of the manipulator will be definitely confirmed by a research that should evaluate the influence of the construction elements on the acoustical free field in an anechoic chamber.

Abstract: The paper presents the structure of control section of measurement manipulator for acoustical tests in anechoic chamber. The specific of that kind of measurements brings up the need of measurement microphone positioning in many points of the measurement space accordingly to relevant standards. In most cases during the tests it is necessary to position the microphone in certain points on the hemisphere. The paper presents hardware structure and software to control the measurement manipulator accordingly to a specified algorithm. A modular construction of manipulator was chosen, which is composed of industrial turntable and two linear motion modules. That solution means that the device under test fixed on the turntable rotates in the range of 2π, and the measurement microphone moves on the track of one quarter of a circle.